Pneumatic method and apparatus for forming metal articles



Feb. 5, 1934. T. M. HIESTER 1,946,211 PNEUMATI METHOD AND APPARATUS FOR FORMING METAL ARTICLES Filed July 10, 1931 2 Sheets-Sheet 1 INVENTOR THEODORE M. H/ESTER'.

MMJQOM ATTORNEY Feb. 6, 1934.

T. M. HIESTER PNEUMATIC METHOD AND APPARATUS FOR FORMING METAL ARTICLES Filed July 10, 1931 2 Sheets-Sheet 2 J 3/ H 2.9 I r H I Illun 30 29 .J 30 "'k L v I INVENTOR THEODORE M H/ESTER.

BY Mjfiii ATTORNEY Patented Feb. 6, lhg'i i FEQE Theodore M. iiicster, Dayton, Ohio, assignor to United Aircraft Products, Inc, Dayton, Ohio,

a corporation of ()hio Application July 10, 1931.

10 Claims.

My invention relates to a method and a machine for forming a simultaneously pressing and reducing the thickness of a metal sheet without disturbing the intermediate and surrounding portions of the sheet so formed and pressed.

In particular, it is the object of my invention to provide forming and pressing tools which will be forced outwardly or away from the work as the form and work move relatively to one another and the tools are correspondingly forced away from one another; and, in such connection, to provide a pressure means which will continuously maintain uniform pressure on the work and the tools so as to secure a uniform result, irrespec-- tive of the tool positions.

It is a further object to provide means having the above advantages which may be rotated at any desired speed.

Referring to the drawings:

Figure l is a side elevation, partially in section, showing two or three tools in a group in engaging position over the top of an article to be formed and pressed;

Figure 2 is a view showing the tools in position at the bottom of the work after the pressing and forming operation;

Figure 3 is a top plan View, partially in section, showing the arrangement of the tools at the top of the Work as they are about to come downwardly;

Figure 4 is a side elevation of a modified form of tool holder specially designed for high speed rotation in that centrifugal force has a very small amount of effect upon the tools as distinguished from the form shown in Figures 1, 2 and 3 where the heavy tool members acting as pistons at high speeds are subject to considerable centrifugal force which may make their action slightly erratic, but for heavier and slower jobs the construction of Figures 1, 2 and 3 is satisfactory.

Referring to the drawings in detail, 1 is a support or shaft adapted to rotate at the desired speed and having therein an air passageway 2 communicating with horizontal air passageways 3. This rotating member 1 is surrounded by a hollow sleeve i having an annular passageway 5 which communicates with a plurality of air pipes 6 leading to the cylinders 7 that are supported in the brackets 8. These brackets 8 are formed on the surface of the hub 9 which is an extension of the shaft 1. The hub or head 9 is supported by a collar 10 attached to any suitable bracket. This collar is provided with bearing plates 11 and 12 on either side thereof. The hub .9, arms 8 and shaft 1 are driven by the gear 13 Serial N 0. 549,859

from a suitable source of gearing or by any desired source of power in order to impart rotation to the hub 9 and shaft 1.

The cylinders 7 are provided with tool pistons 14, the noses of which are provided with tapered heads 15 having working points 16 that are arranged for diagonal movement. The diagonal and downward movement of these points as they rotate in a spiral path acts to press and form the metal in the area 1'7 and reduce its thickness 66 V from that at 18 and 19. This metal is mounted upon a suitable form 20 over which it is pressed and formed.

During this operation the tool pistons 14 are telescoped within the cylinders 7 but this tele- 1 scopic action is evenly and yieldingly resisted by the air, gas or fluid behind the pistons 14 within the cylinders 7 and the adjacent supply lines communicating therewith.

It will be understood that as the tool holder I and the tools descend they are forced backwardly due to the conical shape of the form 20. They should be held uniformly with uniform pressure against the metal in order to give it a uniform shape and thickness as at 17. This cannot be done until some compensatory mechanism is employed which will automatically accommodate the tools to the variations in the form over which the metal is being pressed and formed.

Air, water and oil are cheap and satisfactory mediums for this purpose. They are supplied from a constant source of pressure, such as an air compressor or pump with suitable by-passes that contain uniform pressure with sufficient storage capacity to permit of a portion of the liquid to back through the system while, at the same time, maintaining substantially uniform pressure.

Turning to the form shown in Figure 4 the head 1 is formed with a tool head 21. This head 1 is reciprocated and rotated by suitable mechanism, as by being attached to a drill press. On the tool head are pivoted at 22 depending arms 23 having angular extensions 24 on which are mounted rollers 2 The lower ends of these arms are provided with forming tools 26 which are adapted to engage the surface of the metal 17 to press it downwardly and to form it on the form 20.

The tool head 21 has a slot 27 in which the tool arms reciprocate. As the tool arms pass downwardly over the form so and the metal thereon from the point designated A to the point designated B they are caused to move outwardly and diverge. They do this against the uniform resistance of the air at 28 in the air cylinder 29 1 carried in the bracket 30 on the head 1. This cylinder 29 is provided with a piston 31 and a piston rod 32 which has a thrust head 33 on the end thereof engaging the roller 25 so that, as the tools are caused to diverge by following the form 20 the pistons 31 are forced upwardly against the resistance of the air which is supplied through the pipes 6 from a common supply source 2.

The advantage of the construction of Figure 4 is that high speed centrifugal movement does not affect the positions of the pistons, piston rods and thrust heads 33 and the weight thereof does not have any eifect due to centrifugal force due to the air pressure in the area 28 so that resistance to the arms 23 is secured.

It will be understood that I desire to comprehend within my invention such modifications as may be necessary to adapt it to varying conditions and uses.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In combination, in a machine for forming and extruding metal, a tool having a working point, a form, means of reciprocating one with respect to the other, and fluid pressure means for maintaining said tool in engagement over said form therewith at a uniform pressure.

2. In combination, a plurality of converging tools, iluid pressure means adapted to move tools inwardly towards each other, a form, nose to reciprocate said tools and rotate them w respect to said form whereby as said tools are forced outwardly by the downward movement of said tools over the form said fluid pressure means serves to maintain them with an even pressure on said form at all positions of the tools.

8. In combination, in a machine for forming and pressing metal, a plurality of converging tools having pressing and forming ends at their converging points and formed into pistons at their other ends, a plurality of cylinders for receiving said pistons, and a common source of fluid pressure deliverable into the rear of said cylinders for actuating said tools towards each other and for uniformly and yieldingly resisting the telescopic action of said tools within said cylinders.

4. In combination, in a machine for forming and pressing metal, a plurality of converging tools having pressing and forming ends at their converging points and formed into pistons at their other ends, a plura 'ty of cylinders for receiving said pistons, a common source of fluid pressure deliverable into the rear of said cylinders for actuating said tools towards each other and for uniformly and yieldingly resisting the telescopic action of said tools within said cylinders, and means to rotate and reciprocate said tools bodily as a unit.

5. In combination, a reciprocating and rotating head, a plurality of diverging arms therefrom, a plurality of cylinders carried thereby, a plurality of reciprocating pistons and piston rods therein, and pressing and forming tools mounted on the ends of said rods converging towards one another whereby as said head rotates and descends said tools are caused to follow over a divergent form, the pistons are telescoped within said cylinders and a yielding uniform pressure is maintained upon said tools.

6. In combination, a reciprocating and rotating tool head, a plurality of tool arms pivoted thereon depending therefrom, arms on said tool arms extending upwardly and outwardly there from, a plurality of cylinders arranged on the head over said upwardly and outwardly extending arms, pistons and piston rods in said cylinders, said rods engaging the free ends of said upwardly and outwardly extending arms, and a source of fluid pressure communicating with each of said cylinders behind said pistons for uniformly and yieldingly resisting the outward movement of said tool arms.

'7. In combination, a reciprocating and rotating tool head, a plurality of tool arms pivoted thereon depending therefrom, arms on said tool arms extending upwardly and outwardly therefrom, a plurality of cylinders arranged on the head over said upwardly and outwardly extending arms, pistons and piston rods in said cylinders, said rods engaging the free ends of said upwardly and outwardly extending arms, a source of pressure communicating with each of said cylinders behind said pistons for uniformly and yieldingly resisting the outward movement of said tool arms, a head on each of said piston rods, and a roller engaging said head on each of said upwardly and outwardly diverging arms.

8. In a method for forming and shaping a predetermined area from a portion of a metal sheet, a form supporting the sheet, a forming tool adapted to engage with the portion of the sheet to be form d over the form, means for moving the tool do nwar ly and rotatively over the surface of the metal, pressing it over the form in a flat spiral and fluid pressure actuated means adapted to adjustably press said tool against the metal to con m the metal to the form and reduce the thlCKl'lQSS of the metal in the area so being changed as to form.

9. In a method for forming and shaping a predetermined area from a portion of a metal sheet, a form supporting the sheet, a forming tool adapted to engage with the portion of the sheet to be formed over the form, means for moving the tool downwardly and rotatively over the surface of the metal, pressing it over the form in a spiral path, fluid pressure actuated means adapted to adjustably press said tool against the thickness of the metal in the area so being changed as to form, and means for moving the form and tool means relatively to one another during the forming operation.

10. In a machine for forming and shaping a portion of a metal sheet without disturbing the thickness or configuration of the remainder of the sheet, a form, a plurality of forming tools angulariy disposed with respect to the form surface, means for moving said forming tools rotatively and downwardly bodily over the surface of the metal as it is pressed over the form, means for modifying the distance between the forming tools as the forming of the metal progresses, and fiuid pressure means for adjusting the pressure on the tools irrespective of their position in order to provide a uniform change of the metal being worked upon as to thickness and configuration.

THEODORE IvI. HIESTER. 

